An ongoing project by The Illinois State Archives in collaboration with the Illinois State Genealogical Society compiles all Illinois marriages records that occurred prior to 1901. It currently has in excess of a million pre-1901 data on file, dating as far back as 1763. This information is open for viewing and any member of the public can access or even contribute to them.

Ideally, these marriage records are available on the internet. Dating back fro, before 1900, marriages that also took place after 1900 till now are also accessible as seen with the State-wide Marriage Index. Once they are in the Index, they can be found online which eradicates the long processing procedure at the walk-in offices such as the relevant government agencies.

The information are mainly tapped from the original marriage files that are placed under the official custody of the various County Clerks. Marriage registers, licenses, certificates are examples of documents included in the compilation. Publications of county genealogical societies and private individuals provide additional information.

Data found in these public records include the specifics of the couple such as their names, their parents' names, witnesses to the marriage agreement, the official of the ceremony, the date, county and state the marriage took place in as well as the license insurance. Moreover, if persons with multiple marriage records were to be researched, they would all be produced upon that search with the person's surname. But as states keep their own records, one a record is not found in one state, you can always search for it in another state.

The Illinois Statewide Marriage Index lists information which have been officially kept since they were first documented and filed. The Great Fire of Chicago in 1871 did destroy a good many public records but the Illinois Regional Archives Depository System (IRAD) today still has in its holdings of more than 70 of the 102 counties in Illinois. The surest bet are the individual County Offices and they are the only authorized agencies for certified copies but fees are required.

Another accepted option is the online commercial information brokers. Even though fees are attached, they provide an easy and convenient way to obtain such documents. Ideally, these fees are usually low making them all the more impressive with that superb quality they offer. By utilizing private and proprietary sources, the top commercial providers are always capable of delivering extras over the public walk-in agencies.